And please, please tell me what's wrong with using e.g. <amp-youtube>? It's just a web component! All it does is what you want it to do, and if it doesn't do what you want then either you shouldn't do that, or you can just submit a PR.
The whole point of AMP is 1) make sure the developer doesn't do anything that'll make the page load unnecessarily slowly or repaint/relayout unnecessarily and 2) make it way easier for the developer to accomplish #1 because all you have to do is type <amp-youtube>.
AMP is no different from, say, jQuery, or React, or Angular. It's a different way of doing things, but it's not a "gatekeeper" on the web. It's just another option, one more tool in your belt, if you so choose.